1. Field of the Invention
The invention relates generally to circuit interrupters and, more particularly, to operating mechanisms for circuit interrupters, such as a battery disconnect apparatus.
2. Background Information
Circuit interrupters, such as, for example, battery disconnect switches, are employed to provide protection for the electrical power circuit of a vehicle. For example, some vehicles, such as trucks and cars, employ direct current (DC) disconnecting switches to provide a rapid mechanism to disconnect batteries or other DC power supplies in the event of serious electrical faults. Disconnecting switches may also be employed by vehicles such as, for example, electric vehicles such as golf carts and fork lifts, to disconnect alternating current (AC) power supplies.
Battery cable circuit protection devices, such as battery disconnect devices (BDDs) and battery cut off switches (BCOs), are known to be employed, for example, to disconnect the electrical system (e.g., without limitation, 12 VDC; any suitable DC or AC voltage) of the vehicle in response to a significant collision, or for maintenance during periods of inactivity. Such devices typically employ an operating mechanism having a movable electrical contact which is moved into and out of electrical contact with a number of stationary electrical contacts electrically connected to the battery cable. The movable electrical contact sometimes has a tendency to undesirably separate from the stationary electrical contact(s) when the vehicle is subjected to various shock and vibration loads (e.g., without limitation, rough terrain; pot holes; sudden stops; abrupt turns; collisions). Among other disadvantages, such unintentional separation of the electrical contacts presents an arcing hazard.
Prior proposals have attempted to accommodate such loads by employing an operating mechanism for the battery disconnect device which, for example, has an arrangement of springs, levers and/or solenoids. However, such designs are relatively complex, and thus expensive. Additionally, if the movable electrical contact is brought into electrical contact with the stationary electrical contact(s) too rapidly, it can undesirably bounce with respect to the stationary electrical contact(s), resulting in the undesirable arcing hazard noted above. Solenoids are generally fast-acting and can produce this undesirable result if utilized improperly. Solenoids can also be relatively large, heavy and expensive.
For instance, in some conventional mechanisms, the cam member directly drives the opening and closing of the electrical contacts. As such, the cam member generates the entire force required to move the contacts. Over an extended period of time, the force required of the cam member may cause deformation of the member and thereby, preclude its proper operation.
There is a need, therefore, for an improved operating mechanism for circuit interrupters, such as a battery disconnect apparatus, which not only provides resistance to arcing hazards caused, for example, by unintentional separation of the electrical contacts of the apparatus, but which is also relatively small, lightweight and cost-effective.
There is, therefore, room for improvement in operating mechanisms for circuit interrupters, such as a battery disconnect apparatus.